The present invention relates to a method for Internet Access as described in the preamble of claim 1, a related system as described in the preamble of claim 4, and related devices as described in the preamble of claims 7 and 10.
Such a method for Internet Access is already known in the art, e.g. from the section DNS xe2x80x94Domain Name System, pages 622-631, in xe2x80x9cComputer Networksxe2x80x9d third edition, from the author Andrew S. Tanenbaum.
Therein it is described that, a name system NS, called a Domain Name System, is queried by a requesting host, called xe2x80x9can application programxe2x80x9d. The requesting host provides the Domain Name System with the host-name of the host to be contacted. The Domain Name System then starts searching for the internet address and if it is found, returns the internet address called the IP-address, to the requesting host.
If a first host tries to contact a second host connected to the Internet, it will generally not know the internet address of the second host, but only a host name. Therefor, it will give the host name of the second host to the name system NS, which returns the internet address of the second host to the first host. In case the second host is not active (i.e. not connected to the internet), no internet address is assigned to this second host and consequently there is no internet address available in the name system NS. At a request for the address of this second host, the involved name system returns to the initiating host that the second host is unknown.
An object of the present invention is to provide a method for Internet Access of the above known type but wherein the second host can be reached at any time without the need of a permanent internet connection.
According to the invention, this object is achieved by the method as described in claim 1, the system described in claim 4 and the devices as described in the respective claims 7 and 10.
Indeed, due to the fact that the Name System NS, in case of non-availability of internet address takes the initiative to request the access node AN with the host to be contacted to establish a connection. By establishing the connection between the access node AN and the host to be contacted, an internet address is assigned to the host. The access node AN then returns the assigned internet address to the Name System NS which in its turn returns the internet address to the requesting host.
Another characteristic feature of the present invention is defined in claims 2, 5 and 8.
The name system NS functionality can be performed by a distributed Domain Name System DNS as described in the above cited prior art article.
Further characteristic features of the present invention is defined in claim 3, 6 and 9.
The name system NS functionality can be performed by a gatekeeper. The functionality of this gatekeeper is defined in ITU-standard H.323xe2x80x9d: AUDIOVISUAL AND MULTIMEDIA SYSTEMS: Infrastructure of audiovisual services xe2x80x94Systems and terminal equipment for audiovisual servicesxe2x80x9d